The
Experimental Drainage Field at the SEPAC facility was initiated
in 1983 by researchers in Purdue's Departments of Agronomy and Agricultural
& Biological Engineering.

The
objective of the research on theses plots is to quantify pesticide
and nutrient movement into tile drainage water from a silt loam
soil managed under typical agricultural practices.

The
15-acre facility includes six individually tiled and instrumented
plots at three spacing intervals. These plots are large enough for
a tractor with standard equipment to do standard management practices.
Each plot is an isolated sample collection area with automatic surface
or subsurface samplers controlled by flowmeters.

With
knowledge gained from this research, the impact of management strategies
on tile-transported agricultural chemicals under typical southern
Indiana soils may be evaluated.

With
a length of 225 meters (740 ft) and a width of at least 5 meters
(16 to 66 ft) the plots are large enough for a tractor with standard
equipment to do standard management practices. These plots were
under continuous corn for ten years and are now under corn-soybean
rotation.

The tiles under the 5-, 10-, and 20- meter plots are connected to
tipping bucket flow gauges. The gauges connect to a computer, which
acts as a datalogger and also triggers an automatic sampler after
a preset amount of flow.

Drain
tiles were established on the margin of each plot, so that each
plot is an isolated sample collection area with automatic surface
and/or subsurface samplers controlled by flowmeters. The tiles allow
measuring, monitoring, and subsurface sampling as rainfall on the
plot flows through the soil. The volume of water and concentration
of transported chemicals can be determined for each plot as frequently
as desired.